Gravity drop



June 26, 1923.

J. DOWNIE GRAVITY DROP Filed Mar ch '7.

1922 2 Sheets-Sheet l INVENTOR dbl? flan/me ATTORNEY June 26, 1.923.

I I 1 L 7 II'L 25 3/ 32 56 30 28 2 H W; 7 EFL-#4 T'TTTr- F P7? "T 14,34I ,1: 1 c. L T INVENTOR a 2/' :3- w fo/zn flan/axe /i 38 8 BY FAA24/21/1413,, '6 ATTORNEY Patented June 26, 1923.

barren stares ll r JoHN nowNIE, or snar'rtn, WASHINGTON.

GRAVITY DROP.

Application filed March 7,1922. Serial No. 541,735.

7/; all whom it may concern i Be it known. that 1, JOHN Downin, acitizcn of the United States, residing at Seattle, in the county of Kingand. State of \Vashington, have invented a certain new and usefulImprovement in Gravity Drops, of which the following is a specification.

My invention relates to improvements in gravity drops for lowering heavyarticles and the object of my invention is to provide gravity drop bywhich heavy articles may be quickly and easily lowered any desireddistance and the gravity drop carriage returned to the upper end of ashaft in which it operates without the use of any externally appliedpower the weight of the heavy article that is being lowered serving toraise certain countel-weights by which the drop carriage is afterwardsmoved from the lower to the upper end of the drop shaft when the heavyarticle has been removed therefrom. y

Another object is to provide a vertically movable gravity drop having acompensating or shifting weight in the form of a heavy chain one end ofwhich attached to the drop carriage and the other end of which isattached to a counterweight in such a manner as to cause the weight ofthe chain to be gradually shifted or transferred from the carriage tothe counterweight or from counterweight to the carriage as the two movein opposite direction in the shaft, the weight of the chain being alwaystransferred from the downwardly movingmemher to the upwardly movingmember.

Another object is to provide novel brake means that are arranged to heapplied as the gravity drop carriage approaches the limit of itsdownward movement to check the speed of descent of the carriage.

Other and more specific objects will be apparent from the following;description taken in connect-ion with the accompanying drawings.

The device shown and described in this application is designedespecially for use in lowering: semi-cylindrical stereotype plat es ofthe form commonly used in newspapers printing plants, but it will beunderstood that such device may be readily adapted for lowering variousother forms of heavy articles without altering the general plan ofconstruction and method of the same.

In the accompanying drawings, Figure 1 is a somewhatdiagrammatic viewpartly in vertical section and partly in elevation of a gravity dropshaft provided in accordance with my invention, the drop carriage beingshown at the upper end of the shaft;

Fig. 2 is a similar view showing the drop carriage at the lower end ofthe shaft;

Fig. 3 is a fragmentary sectional view of the bottom end of the dropshaft showing certain curved guideways and certain catch and releasemeans in elevation;

Fig. 4 is a detached view in perspective of a detail of the invention;

Fig. 5 is a view partly insection and partly in side elevation of thedrop carriage;

Fig. 6 is a view in front elevation of the drop carriage portions of thedrop shaft being shown in section;

Fig. 7 is a view in cross-section on a reduced scale substantially onbroken line 7, of'Fig. 6; and

Figs. 8 and 9 are fragmentary views partly in section and partly inelevation illustrating different details of my invention.

Referring to the drawings, throughoutivhich like reference numeralsdesignate like parts, the numeral 10 indicates a vertically arrangeddrop shaft of rectangular cross sectional shape and having on oppositesides continuous t-rackways 11. on which a drop carriage is guided forvertical move-' ment.

The gravity drop carriage is formed, in partcof two vertical spaced,parallel side members 12 that are each provided near their top andbottom ends with channel shaped guide pieces: 13 that fit. over andslide nponthe trackways 11 and that are rigidly secured together at thetop and bot tom by transverse upper and lower frame bars let and 15respectively. i

A. frame for the support of certain bralre devices and brake operatingmechanism 1s formed by a horizontal. bar 16 that is disposed parallelwith and at a distance from the upper frame bar 14 andthat is rigldlysecured to the carriage frame by angular truss braces 17 and horizontalplates or bars 18 which are provided at both ends.

Mounted within the frame of the drop carriage and movable verticallywith respect thereto is a cradle for the reception of the load or heavyarticles, which may be semiand are rigidly secured together at theirupper extremitiesby short angle bar sections 23. The angle barsections23 re provided wi.th outwardly protruding I spaced apart lugs24' that fit on opposite sides of the inwardly protruding flanges of theside frame members 12 and guide the-cradle for vertical movement on thecarriage frame.

The upper ends ofthe members 21 and 22 on opposite sides of the cradleare rigidly secured together by transverseangle bars 25 andthe lowerhorizontal portions of the members2l and 22 are connected by spacedangle bars 26 and 27 that are disposed adjacent to the opposite sides ofthe cradle and have theirhorizontal flanges turned out wardly so thatthe edges of the stereotype plate 20 may rest thereon as shown in Fig.and be guided by the vertical flanges of such bars 26 and 27. Thevertical flanges of the bars 26 and 27 are bent inwardly as at 28 attheir front ends and serve as guides to assist in positioningthestereotype plates 20 on the cradle.

The bars 26 and 27 connected with each other midway of their length by across bar 30 whose ends project outwardly past the bars 26 and 27 andare notched as shown in Fig. 7, sothat they fit over the flanges of theframe members 12 and co-operate with the lugs 24 in supporting thecradle so that it may be moved vertically with respect to the carriageframe.

The cradle is arranged to be supported from below by a bent supportingrod, as shown, comprising longitudinally aligned bearing portions 3l,that are connected by an arch-likesupporting portion 32 and one ofwhichis bent at right angles to form a lever arm whoseouter end is againbent at right angles and is provided with a roller The bearing portions31 are arranged to be journalled in bearing brackets 35 on the cross bar15 and the arched portion 32 is provided'with a suitable lug36 to whicha tension spring 37 maybe secured.

The tension spring 37 is connected with the upturned end of The medialcross bar 30 of the cradle is provided with a rearwardly projectingrigidly secured plate 40 that is arranged to rest 'upo'n th'e archedportion 32 of the supportrod when such rod is in the upright positionshown inr'igs. 5 and 6. v r

A bolt 41 is rigidly secured to the bracket 7 and frame bar 15 and isslidable through suitable perforation in the plate. 40, which I H abracket 38 that is rig d with the frame bar 15.

bolt serves as astop for the arched rod portion 32 and also serves tolimit the upward movement of the cradle with respect to the carriage orframe.

7 The cross bars 25 at the uppereiitremity of the cradle are connectedby a U shaped 'bolt l2 with a leverarm 43 the rear end of brake shoe 4L6withthe lower member 47 of a two part turnbuckle.

The upper member 48 of the turn buckle is pivotally connected with. alever arm 50 that is fulcrumed between bracket pieces 51 that are rigidwith the frame 16 and that extends crosswise of and rests upon'brakeshoes 52. The upper and lower brake shoes 52 and 46 respectively areboth of somewhat flexible metal and have suitable extensions that aremade fast to fixed portions of the frame, the upper brake shoe 46 beingsecured to a rigid bracket 53. The curved brake portions of both theupper and lower brake shoes are lined with brake lining 54 that isdisposed tofrictionally engage with a brake drum orpulley 55 on a shaft56 that is journalled in bearings 57 son the frame bars Hand 16. i

The forward end of the lever arm 43 is supported on a screw 58 when thebrake is not applied to the brake drum, said screw 58 being adjustablyconnected with a bracket 60 that is afiixed to the frame bar 16.

The upper andlower portions 48 and 47 of the turn buckle are adju'stablysecured together by a. bolt 49 which constitutes brake adjusting means.i

The drop carriage is supported for vertical movement in the drop shaftby a sprocket chain 62 that has one end secured as at 63, to an overhead support 64, thence passes downwardly around a sprocket wheel 65 onthe shaft 56,.thence upwardly over an idler sprocket 66 on ashaft thatismounted on the over head support 6 L, thence downwardly around an idlersprocket 67 on the upper end of a counterweight 68 and thence upwardlyto and is secured as at 70, to the over head support64.

The counterweight 68 is guided for vertical movement by two T shapedtrack bars 71 that are supported in spaced apart parallel relation byrectangular brackets 72 that may be secured to the exterior ofthe wall10 of the drop shaft.

A brake drum or pulley 7 3 is preferably.

secured to the shaft 69 on which the idler sprocket 66 is carried and a.brake shoe 7a is arranged to rest upon and retard the ro- ;tation of thedrum 73 said brake Shoe being lln arranged to have weights removablyplaced thereon whereby the retarding effect of the same may be increasedor. diminished.

A relatively heavy chain 76 of substantially the same length as the dropshaft has one end secured to the bottom of the drop carriage and theother end secured to the counterweight 68 in the manner shown so that asthe drop carriage and counter weight move up and down the weight of thechain is gradually shifted from the downwardly moving member to the up--wardly moving member.

The drop carriage is securely held in its uppermost position by a catchmember 77 that is hinged to a stationary supporting member 78 andarranged to hook beneath a plate 79 that is secured to and projectsrearwardly from the cross bar 25 at the top of the cradle. A compressionspring 80 yieldingly urges the catch member outwardly and interlockingstaple members 81 limit the movement of the catch member -1n response tothe pressure of the spring 80. The lower end of the catch member extendsdownwardly and is bent into substantially the shape shown in Fig. 5, toform a trip arm 82 with which a stereotype plate 20 may engage to causethe catch member 77 to release the drop carriage. I

Inwardly curved springs 83 of flat metal are secured to the trackways 11near the upper end of the drop shaft to arrest the movement of the dropcarriage as it approaches the uppermost position.

The drop carriage is retained in its lowermost position by a catchmember 84 having hook elements 85 thatare arranged to hook into aperforation or, slot 86 in the front bar 21. of the cradle. The catchmember 84 is normally held in an operative position by a tension spring87 and is arranged to be moved outwardly to cause it to release the dropcarriage by pivotally mounted foot lever 88 whose upper end engages thecatch member 84 and whose lower end projects through the front wall ofthe front wall of the drop shaft. The upper end of the catch member 84is curved, as shown so that when the drop carriage descends the bar 21will encounter said curved end, and move the catch member outwardly.

A curved strip 90 is secured to the side wall of the drop shaft near thebottom thereof, as shown in Fig. 3, to form a slot 91 into which theroller 34 on the end of the member that normally supports the weight ofthe cradle and loatl may enter as the carriage nears the bottom of theshaft and a. block 92 is provided near the top end of the curved stripto prevent thesame from being abruptly deflected from its normalposition.

In operation when the drop carriage is at the top of the shaft the catchmember 77 will be hooked beneath theplate 79 and will hold the dropcarriage in a fixed position so that a stereotype plate 20 may be easilyinserted at the open front of the shaft placed on the cradle, as shownin Figs. 5 and 6, and moved rearwardly until it strikes against the triparm 82 and releases the carri age whereupon the combined weight of thestereotype plate, carriage and chain 76 will cause the carriage todescend rapidly until the roller 34 on the end of the rod member onwhich the cradle rests encounters the curved strip 90 and passes intothe slot 91 near the bottom of the drop shaft thus causing the archedportion 32 of the cradle supporting rod to be moved out from under theplate 40, as shown in Fig. 8, so that the weight of the cradle andstereotype plate will be transferred and will hang from the lever arm 43thus causing the linings 54 on the upper and lower brake shoes 52 and 46to be applied to the brake drum 55 with sufficient force to arrest thedownward movement of the loaded carriage and bring the same to a stop insuch aposition that the lower catch member 84; will engage within theslot 86 and lock the carriage in the lower position. I

As soon as the stereotype plate 20 has been removed from the cradle thesprings 44: will lift the weight of the cradle and release the brakes 46and 52 sothat when the catch member 8a is withdrawn from engagement withthe carriage by depress ng the lower end of the foot lever 88 suchcarriage will be rapidly moved upwardly to the top of the shaft by thecombined weight of the chain 7 6 and counterweight 68.

The weight of the chain 76 is shifted from the counterweight to thecarriage and vice versa as the counterweight and carriage move up anddown, when the carriage is at the top of the drop shaft the majorportion of the weight of the chain is suspended from said carriage andtends to pull the carriage down when it is released but as the carriagedescends the weight of the chain shifts to the counterweight thustendingto slow up the speed of descent of the carriage as it approachesthe bottomo f the drop shaft and at the same time causing the chain toassume such a position that its weight will be effective in helping tostart the carriage upward from the bottom of the shaft after the loadhas been removed therefrom. As the carriage approaches the upper end of.the drop shaft in its upward movement the gradually shifting weight ofthe chain 76 causes the several parts to assume a substantially balancedrelation and the speed of movement of the carriage to be checked beforeit encounters the spring 83 and is 1 stopped.

movement of the various parts and to prevent the link belt 62 from beingthrown off of the sprocket wheels over which it passes.- The set screw58 and the bolt 49 in the turnbuckle that connects the lever arms 43 and50 permit the brake mechanism to be adjusted to suit various loads andto regumethod of operation of my invention, while I have shown anddescribed whatl now consider to be the preferred embodiment of myinvention it will bennderstood that the disclosure is merelyillustrative and that such changes may be made as are within the scopeof the following claims.

'VVhat I claim is: I

1. A device for lowering heavy objects including a carriage, acounterweight connected with said carriag a cradle on said carriagearranged to receive a load, brake mechanism. for retarding the movementof said carriage and means actuated by the weight of said cradle and itsload for rendering said brake mechanism operative.

2. A device for lowering heavy objects includingfa vertically movablecarriage, a

counterweight connected with said carriage,

a load receiving'cradle movable in said. carriage, releasable devicesfor normally supporting said cradle in a fixed position with respect tosaid carriage, brake mechanism mounted on said carriage and connectedwith said cradle whereby downward movement of said cradle on saidcarriage will. apply said brake mechanism and. means for automaticallyreleasing said cradle supporting devices to permit said brake mechanismto be i applied as said carriage approaches its lowermost operativeposition.

3. A' gravity drop of the class described including a vertical elevatorshaft, a carriage guided for movement in said shaft, a counterweightconnected with said carriage,

a load receiving cradle movablydisposed within said carriage releasabledevices on said carriage for. normally supporting said cradle. brakemechanism mounted on said carriage. suspension means connecting saidbrake mechanism and said cradle and means near the lowermost end of sa delevator shaft for automatically releasing said cradlesupporting deviceswhereby the weight of said cradle and its load will cause said brakemechanism to he applied as said carriage approaches thebottom of theelevator shaft. I i. A gravity drop of the class described including anelevator shaft, a carriage guid ed for movement in said shaft, a rigidframe structure at the u'pper end of said elevator shaft, acounterweight,flexible devices con nected with saidfframe structure andsupporting said carriage and said counterweight for movement lengthwiseof said elevator shaft, a brake drum mounted on said *arriage andarranged to be rotated by said flexible carriagesupporting devices assaid carriage moves within said elevator shaft, brake shoes arranged toengage said brake drum, lever arms connected with said brake shoes, aload carrying cradle movably supported on said carriage and connectedwith said lever arms, means on said carriage for normally supportingsaid cradle and devices adjaren't the bottom of said elevator shaft formoving said cradle supporting means to release said cradle and permitsaid cradle to hang from said lever arms and ap-. ply said brake shoesto said brake drum as said carriage approaches its lowermost operativeposition. v y

5. A gravity drop of the clas described including a carriage, meansfor-guiding said 'carriag v for vertical movement, a shaft journalledinthe upper'portion of said carriage, a brake drum secured on said shaft,a pulley secured on, said shaft, flexible carriage supporting meanspassing around said pulley and arranged to rotate said brake drum assaid carriage move up and down,

for normally supporting said cradle" and..

means connectingsaid cradle with said brake shoes and arranged to pplysaid brake shoes to said brake drum when said cradle supporting means ismoved to release said cradle.

6. A gravity drop of the class described includil'xg a carriage, meansfor guiding said carriage forvertical movement, a shaft mounted forrotation on said carriage, a sprocket wheel secured on said shaft, asproclret chain passing around said sprocket wheel and arranged "tosupport said can riage for vertical movement, va counterweight connectedwith said sprocket chain, a. brake drum on said shaft, brake shoesarranged to engage with i said intake drum, lever means connected withsaid brake shoes, a load carrying cradle suspended from said levermeans, springs connected with said lever means for supporting the weightof said cradle when the same is not loaded and for permitting saidcradle to apply said brake shoes to said brake drum when said cradle isloaded and releasable means on said carriage for supporting said cradleindependently of said brake means. 7. A gravity drop of the classdescribed including a carriage, a shaft mountedjfor rotation on saidcarriage, carriagesupporting means arranged to rotate said shaft as saidcarriage is moved vertically, a brake drum on said shaft, brake shoesdisposed on opposite sides of said brake drum, lever arms for applyingeach-of said brake shoes to said brake drum; adjustable turnbuckle meansconnecting said lever arms; a load carrying cradle movable vertically insaid carriage, means connecting said cradle with one of said lever armswhereby Weight on said cradle Will tend to apply said brake shoes tosaid brake drum, resilient means connected with said lever arms tocounteract the Weight of said cradle, a pivotally mounted arch like rodmember mounted on said carriage below said cradle for supporting saidcradle when in an upright position, an outwardly protruding lever arm onsaid rod member, and means adjacent the path of movement of saidcarriage for engaging said outwardly protruding lever arm and turning;-said arch like supporting member into an inclined position to releasesaid cradle and apply said brake shoes to said brake drum. i

In Witness whereof, I hereunto subscribe my name this 1st day of MarchA... D. 1922.

JOHN DoWNiqE.

